A Y-shape connection for connecting the respective generating coils of the three phases in a star shape (Y-shape), and a Δ-shape connection for connecting the respective generating coils of the three phases in a delta shape (Δ-shape) are known as the three-phase alternating current electric generator for a vehicle building-in the rectifier assembly of this kind.
First, the three-phase alternating current electric generator for a vehicle of the conventional Y-shape connection will be explained. The three-phase alternating current electric generator of a neutral output utilization type for rectifying a neutral output of each of the generating coils of the three phases and further increasing the rectifying output is known as the three-phase alternating current electric generator for a vehicle of the Y-shape connection. For example, the three-phase alternating current electric generator for a vehicle of this neutral output utilization type is disclosed in FIG. 7 of JP-A-9-19119.
In the three-phase alternating current electric generator for a vehicle of the neutral output utilization type of this kind, it is necessary to connect a coil terminal of the neutral side of each of the generating coils of the three phases connected in the Y-shape connection to a neutral diode of the rectifier assembly built in the electric generator. Each of the generating coils of the three phases has the three coil terminals on the neutral side in total. In the three-phase alternating current electric generator of the neutral output utilization type, it is necessary to connect all these three coil terminals of the neutral side to one neutral diode.
In the construction for connecting the three coil terminals of the neutral side to one diode, all the three coil terminals are connected to one connecting terminal of the diode as a result so that it is difficult to make its connecting work.
For example, in a full-wave rectifier assembly, a diode pair connected to the neutral point is constructed by a positive side diode and a negative side diode, and an anode terminal of the positive side diode and a cathode terminal of the negative side diode are overlapped with each other. However, it is necessary to nip all the three coil terminals of the neutral side terminals from each generating coil in a portion in which these anode terminal and cathode terminal are overlapped with each other and are fastened. It is difficult to make such a connecting work.
JP-A-9-19119 discloses a three-phase alternating current electric generator for a vehicle in which the connecting structure of each of the generating coils of the three phases and the rectifier assembly is improved. In this prior art, the use of a special circuit substrate shown in the upper portion of FIG. 1 of this prior art is proposed. In this circuit substrate, a circuit pattern is formed on one surface of an insulating property substrate. The three coil terminals of the neutral side from each generating coil are connected to each other by the circuit pattern. Accordingly, as a result, the diode pair connected to the neutral point is constructed such that one terminal connected to the above circuit pattern is simply nipped between the anode and cathode terminals of this diode pair. Accordingly, its connecting work is simplified.
However, in accordance with this prior art, it is necessary to newly arrange the special circuit substrate between the generating coils of the three phases and the rectifier. This circuit substrate causes an increase in the number of parts built in the electric generator and makes the internal arrangement of a bracket complicated.
The three-phase alternating current electric generator for a vehicle of the conventional Δ-shape connection will next be explained. For example, this conventional three-phase alternating current electric generator for a vehicle of this Δ-shape connecting type is disclosed in FIG. 1 of JP-A-4-42759.
In this three-phase alternating current electric generator of the Δ-shape connection, it is necessary to connect two coil terminals from two adjacent generating coils among the respective generating coils of the three phases to each corresponding diode pair of the full-wave rectifier assembly built in the electric generator. In each diode pair, for example, it is necessary to fasten terminals from the two adjacent generating coils together with the anode terminal of the positive side diode and the cathode side terminal of the negative side diode. Accordingly, it is also difficult to make this connection.
This difficulty can be improved by using a circuit substrate shown in FIG. 1 of JP-A-9-19119. However, the number of parts is increased and the internal structure of the bracket is complicated by using the circuit substrate.
This invention proposes an improved three-phase alternating current electric generator for a vehicle able to simplify the connecting work of the generating coils of the three phases and the diode without increasing the special circuit substrate.